A lot of the top guys started playing the game at a young age, Jonny Wilkinson is the perfect example.
But England forward Danny Grewcock was one player who didn't start until he was a lot older.
Danny Grewcock is now an England regular
Kids are starting to play at a younger age and that's great. But if you are a 17-year-old and you started two years ago, that's fine too.
It's a game you can pick up pretty quickly.
The way the game is played has changed hugely, almost everything about it.
When I was a kid, if you were a second row you used to chase the ball wherever it went and tried to win it for the backs.
But now you need to be a better all-round rugby player than you did 20 years ago.
As a modern second row, you get a chance to run with the ball, make a lot more tackles, pass, catch, kick and have a good understanding of various situations.
And that's the great thing about rugby, you're always learn new things off your team-mates or coaches.
When you play and train with the team, your team-mates are giving each other feedback all the time about what they are doing in the line outs and the scrummage.
You are always passing that feedback around, always picking up new things.
Winning the Rugby World Cup doesn't mean Johnson knows everything
So you've got to be prepared to learn and listen.
I've had young kids of 23 at Leicester telling me things to do in the backline.
People think you've done this and that and you're getting old means you know it all. But you don't.
I learned about the game so many ways, on TV when I was young, watching the Tigers, playing at school and clubs then training with the senior team.
I'm always picking new things up.
And it's not just about individual skills, it's also about the way you handle yourself around other people.